Synthesis of Functionalized Polymers

There is very little new synthetic organic chemistry involved in the synthesis and transformation of polymers. The organic chemistry involved is usually the application of known, solution-phase organic reactions to polymeric chemistry. 

In organic chemistry, hydrocarbons are considered parent compounds, while other organic compounds are considered derivatives. This analogy 

---

Structural control of polymer terminal has been extensively studied since terminal-functionalized polymers, typically macromonomers and telechelics, are often used as prepolymers for synthesis of functional polymers. Various methodologies for synthesis of these polymers have been developed however, most of them required elaborate and time-consuming procedures. By selecting... 

There is a brief reference to electroreductive silicon polymer formation in COMC II (1995) (chapter Organopolysilanes, p 96), but the very limited extent of the field at that time precluded further comment. Since then, the field has seen considerable progress, and the mild conditions have permitted the synthesis of functionalized polymers of moderate molecular weight (104), an example of which is the co-polymer poly(rncthyM-rncthoxymethoxyphcnylsilylene)-r -poly(methylphenylsilylene), 26, with a protected phenolic function, which was prepared with a molecular weight Mw= 19,000.96 Deprotection afforded the phenolic polymer. Several reviews on the area have been published.113-115... 

Some particularities of the extraction of ions from an aqueous organic phase, and of the phase catalyzed polyetherification will be summarized. These will represent the fundamentals of our work on the synthesis of some novel classes of functional polymers and sequential copolymers. Examples will be provided for the synthesis of functional polymers containing only cyclic imino ethers or both cyclic imino ethers as well as their own cationic initiator attached to the same polymer backbone ABA triblock copolymers and (AB)n alternating block copolymers and a novel class of main chain thermotropic liquid crystalline polymers containing functional chain ends, i.e., polyethers. 

Three major topics of research which are based on phase transfer catalyzed reactions will be presented with examples. These refer to the synthesis of functional polymers containing functional groups (i.e., cyclic imino ethers) sensitive both to electrophilic and nucleophilic reagents a novel method for the preparation of regular, segmented, ABA triblock and (A-B)n alternating block copolymers, and the development of a novel class of main chain thermotropic liquid-crystalline polymers, i.e., polyethers. 

Fig, 1-32. Synthesis of functional polymers from hydroboration of p-bromostyrene and coupling reaction catalyzed by PdCl2(dppf) (adapted from [241]). 

Bao et al. [178] have used several bis(stannyl) derivatives [2,5-bis(tributylstannyl) thiophene, l,4-bis(tributylstannyl)benzene, other l,4-bis(tributylstannyl)arenes, -bis(tri-butylstannyl)ethene] in the synthesis of functional polymers. 

The synthesis of functional polymers is not always a straightforward procedure, because of the competition or antagonism of functional groups with the active living ends. Therefore, several protective groups have been used to mask reactive functionality.68... 

It is generally accepted that the eROP of CL is initiated by a nucleophilic attack of a hydroxy compound on the enzyme activated monomer (8-10). Various hydroxy-fimctionalized (macro)initiators have been reported in the past for the enzymatic synthesis of functionalized polymers and block copolymers, respectively (8-11). As outlined above, only a high initiation efficiency of the dual initiator in the eROP leads to high block copolymer yield. This efficiency mainly depends on two factors side reactions caused by competitive water initiation and the initiator design. We achieved the reduction of the water initiation by developing a thorough drying protocol prior to the enzymatic reaction (12). In order to study the influence of the initiator structure, several dual... 

This chapter surveys the synthesis of functional polymers by direct methods, such as anionic, cationic, bee radical and coordination polymerization, as weU as post-polymerization functionalization of chains in the bulk or on the surface. Special emphasis is given to more modem techniques that allow for controlled and directed functionalization via living polymerization. Moreover, an introduction to typical applications of functional polymers is presented. 

It was long believed that cationic polymerization was an unsatisfactory route to synthesize well-defined functional polymers because of inter- or intra-molecular transfer or rearrangement However, in recent years, several monomers have exhibited sufficient control of initiation, propagation and termination to allow the synthesis of functional polymers. Tetrahydrofuran (THF) has been cationically polymerized using the difunctional initiator triflic anhydride (Scheme 4). ... 

Coordination polymerization involves the use of transition metal catalysts. Examples are Ziegler-Natta polymerization by Tl/Al systems, metallocene polymerization with Ti, Zr, Hf catalysts, or metathesis polymerization with W, Mo, Re metals. Synthesis of functional polymers by organometallic catalysts are particularly difficult because transition metds are not only l ed by protic functionality, they are often poisoned by heteroatoms (e.g. N, O). 

One of the primary factors slowing the growth of functional polymers has been the relative complexity and cost of their preparation. The synthesis of functional polymers is often made difficult because of chemical or phase incompatibilities or antagonisms. This chapter surveys the general methods for functional polj er syntheses. It reviews the scope and limtations of functionalization by direct polymerization (e.g. anionic, cationic, free radical and organometallic methods), as weU as post-polymerization bulk and surface modification of preformed backbones. 

Synthesis of Functional Polymers by Atom Transfer Radical Polymerization... 

Boufi Sami, is Professor at the Department of Chemistry of the University of Sfax (FSS). His research activities include chemical modification of cellulose and carbohydrate materials, the synthesis of functional polymer for colloidal chemistry, and the exploitation of chemically modified cellulose fibres as reusable adsorbent for dissolved organic pollutants. 

The synthesis of functional polymers containing silver NP is environmentally friendly, experimentally simple and extremely quick. It opens up new possibilities for the development of antimicrobial coatings with medical and sanitation applications. 

Sawamoto, M., Kamigaito, M., 2000. Controlled synthesis of functionalized polymers by transition-metal-mediated living radical polymerization. Macromol. Symp. 161,11—18. 

Gao, H. Matyjaszewski, K. Synthesis of functional polymers with controlled architecture by GRP of monomers in the presence of cross-linkers From stars to gels. Prog. Polym. Sci. 2009, 34 (4), 317-350. 

Dr. Vikas Mittal studied chemical engineering from Punjab Technical University in Punjab, India. He later obtained his Masters of Technology in polymer science and engineering from Indian Institute of Technology Delhi, India. Subsequently, he joined the Polymer Chemistry group of Professor U. W. Suter at the Department of Materials at Swiss Federal Institute of Technology, Zurich in Switzerland. There he there worked for his doctoral degree with focus on the subjects of surface chemistry and polymer nanocomposites. He also jointly worked with Professor M. Morbidelli at the Department of Chemistry and Applied Biosciences for the synthesis of functional polymer latex particles with thermally reversible behaviors. 

---